Document And Entity Information (USD $)	12 Months Ended
	Apr. 30, 2012	Jul. 02, 2012
Document and Entity Information [Abstract]
Entity Registrant Name	ELECSYS CORP
Document Type	10-K
Current Fiscal Year End Date	--04-30
Entity Common Stock, Shares Outstanding		3,884,012
Entity Public Float	$ 20,857,000
Amendment Flag	false
Entity Central Index Key	0000914398
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Smaller Reporting Company
Entity Well-known Seasoned Issuer	No
Document Period End Date	Apr. 30, 2012
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY